Anti-Hebbian learning rules have been suggested as a mechanism of synaptic plasticity in inhibitory synapses (Barlow & Foldiak, 1989). The basic idea is that the presence of coincidental pre- and postsynaptic activity increases the efficacy of the inhibitory synapse, while its absence decreases inhibitory strength. We investigated the role of anti-Hebbian learning mechanisms for interocular inhibition during binocular rivalry. In binocular rivalry, different images are presented to the two individual eyes. Rather than perceiving a mixed or averaged version of these images, observers typically perceive fluctuations between the two monocularly defined percepts. Computational models aiming to explain these perceptual fluctuations usually implement a form of mutual inhibition between percept-coding neuronal populations. Here we demonstrate that binocular rivalry is at least partially based on low-level cross-inhibition between monocular neurons with a different eye-of-origin, and that there is plasticity in the strength of these interocular inhibitions that is consistent with anti-Hebbian learning principles. We presented observers with prolonged binocular rivalry stimuli and found that the strength of interocular inhibition decreased over time, resulting in a higher incidence of mixed or superimposed percepts. With various stimuli and interleaved changes in eye-stimulus configuration, we demonstrate that this plasticity of inhibitory strength is stimulus- and eye-specific and exist for both simple gratings and more complex house/face stimuli. Further experiments revealed that recovery from ‘lowered inhibition’ only occurs if both eyes receive consistent visual information with similar features as the preceding rivalry stimuli. Neither monocular stimulation nor binocular stimuli with a different orientation and spatial frequency changed the strength of interocular inhibition back to baseline values. We conclude that, consistent with previously proposed anti-Hebbian learning rules, plasticity in interocular inhibition during prolonged binocular rivalry depends on simultaneity of activity in pre- and postsynaptic monocular neurons.